What do you mean by "the AC adaptors"? and to better answer you question, what kind of stats do you have?
Silverarrows - I am on my 6th pair of Martin Logans and have always used an aftermarket AC cord. While I can't say it makes a huge, demonstrable difference, every little thing helps, especially with the high resolution that electrostats are capable of.
I have also read that Logans can benefit from using a power regenerator, such as a PS Audio PowerPlant, set at a different voltage (lower? higher?) setting, but i have yet to attempt this. You can probably find something on this by doing a search through the thread archives here @ the 'gon.
Silver -- I understand now that your stats are powered by a 12V DC wall wart? That's fine, but it won't benefit from any kind of power conditioning/regeneration as the AC/DC adaptor is itself the limiting factor quality-wise.
As for the risk of low power, a drop in wall voltage would probably affect performance, but would not cause damage. In any case, no power conditioner will keep wall voltage from sagging if your power company's supplied voltage fluctuates wildly. A regenerator (not a conditioner!) will hold the votage steady if that's a problem in your area -- you can check your wall voltage at various times of the day and night using a simple volt meter from Radio Shack. It should measure about 117 to 123 volts to be within an acceptable range.